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W. V. TURNER. CAR DOOR MOTOR.

APPLICATION FILED AUG.4. 1916.

1,326,228. Q a Patented Dec. 30,1919.

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WALTER v. TURNER, or WILKINSBURG, rENNsYLvAN-IA, ASSIGNOR TO THE wEsr INGHOUSE AIR BRAKE COMPANY, or WILMERDING, PENNSYLVANIA, A oonro- BATION OF PENNSYLVANIA.

CAR-DOOR MOTOR.

To all whom it may concern:

Be it known that I, WALTER V. TURNER, a citizen of the United States, residing at Wilkinsburg, in. the county of Allegheny and State of Pennsylvania, have invented new and useful Improvements in Oar-Door Motors, of which the following is a specification. I

This invention relates to door. operating motors, and more particularly as applied for controlling the doors of traction cars:

The principal object of the invention is to provide improved means for cushioning the action of the door motor in order to prevent slamming of the car doors. I

In the accompanying drawings; Figure 1 is a diagrammatic view, with the door operating motor in section, of a car door controlling apparatus; Fig. 2 a face view of the rotary valve for controlling the admission and release of fluid under pressure to and from the door operating motor; and Fig. 3 a plan view of the valve seat for said rotary valve.

As shown in the drawing, the door controlling apparatus may comprise a door opcrating motor 1 and a controlling valve device 2 connected 'by pipes?) and 4; to the door motor.

The door motor comprises a casing having piston chambers 5 and 6 connected respectively to pipes 3 and 4 and containing pistons 7 and 8 connected together by a pis- 1 ton rod 9.

The. piston rod ,9 is provided with rack teeth 10 adapted to be engaged by a pinion 11, which, through suitable mechanism (not shown) is adaptedto effect the opening and closing of the car doors when the pinion is rotated by the movement of the piston rod 9;

The controlling valve device 2 contains a'rotary valve12 adapted to be operated by a handle 13 and having through ports 14:

and 15 and a cavity 16-having acentral port opening 17 'and an outer port opening 18. The seat of the rotary valve 12 is provided with a central exhaustport 19 and ports 20 and 21 which communicate respectively with the pipes 3 and 4. Ports 22 and 23 lead to the respective piston chambers 5 and 6 and are connected by the respective pipes 24 and 25 to reservoirs or receptacles 26 and 27 the ports 22 and 23 being so positionedithat when the" corresponding pistonis in its ex- -T If it is desired to close I Specification of Letters Patent. Patented Dec. 30, 11919,

Application filed August 4, 1916. Serial No. 113,096.

trerne outer position, the port is opened to the chamber at the inner face of the piston.

Assuming that when the pistons 7 and 8 are moved to the right hand position'shown in the drawing, the doors are closed, the corresponding position of the valve device 2 will be such that through port 15 registers with port 20 so that fluid is supplied from a suitable source of fiuid under pressure through pipe 3 to piston chamber 5 and in the same position cavity 16 connects port 21 with'exhaust port 19, so that piston chamber 6 is maintained at atmospheric pressure. The pistons 7 and 8 will therefore be maintained in' this position by the fluid pressure .edto ex aust port 19.

Fluid is then supplied-to piston chamber 6 and the pistons are shifted to the left.

'When piston 8 passes over the port 23, fluid is also supplied toreservoir 27 and this reduces the pressure and the rate of increase in pressure in iston chamber 6, so that the .movement of t e piston isretarded and a slower action of the doors is obtained, so that slamming of the doors is prevented.

The. volume of the reservoir may be so proportioned with respect to the volume of the piston chamber that any desired rate of movement can be secured, as will be evident. As the piston 7 approaches its outer seat, theport 22 is passed 'over by the piston, so

' that the port is opened to the chamber at t e innerface of the piston, permitting the fluid remaining in the reservoir 26 to exhaust to the atmosphere, since the inner chamber is open to the atmosphere.

I the doors the handle 13is turned to the position for admitting fluid under pressure to thepiston chamber 5 ind for venting fluid from piston cham- In this case, the movement of the pistons is also retarded by the fiow of fluid into reservoir26 which is connected to piston chamber 6.

It will now be seen that the cushioning of the pistons is brought about without the use of check-valves or other'auxiliary valves, so that a sim le construction is rovided which can be cheaply manufacture and which is not liable to get out of order.

Having now described my invention, what I claim as new and desire to secure by Letters Patent, is:

1. A fluid operated motor comprising a casing having a piston chamber, a piston therein, having one side constantly open to the atmosphere, and a closed reservoir connected to said piston chamber and communicatin in the release position of the piston with the atmospheric side of the piston, and with the fluid pressure side of the piston upon a partial movement of the piston by fluid under pressure.

2. A fluid operated motorcomprising a casing having opposite piston chambers, a piston in each chamber having one side constantly open to the atmosphere and the opposite side adapted to be subjected to fluid pressure, a member connecting said pistons,

and a separate closed reservoir connected to each iston' chamber and communicating with t e fl uid pressure side of the corresponding piston upon movement of said piston by fluid under pressure.

3. A door operatingmotor comprising a plying and releasing fluid to the other side mamas I 0t each piston, and. a separate reservoir of constant volume connected to each piston chamber and opening to the atmospheric side of the piston in its release position and adapted to be charged with fluid supplied to'the piston chamber upon a predetermined movement of the iston.

4., A door opera ing motor comprising a casing having piston chambers containmg pistons connected together for operating the car doors and each piston having one side constantly open to the atmosphere, a manually operated valve-device having positions for supplying fluid to one piston chamber and for releasing fluid from the other, and

a separate reservoir connected to each pis-' tdnchamber and communicating with the fillld pressure side of the corresponding flpiston upon movement of saidpiston' by uid- ,under pressure.

5. A' door operating motor comprising a .casing having a piston chamber, a piston casing having pistonchambers containing pistons connected together for operating the car doors and "having one side of each piston open, to the atmosphere, means for supthereln for operating the door having one sideconstantly open to the atmosphere,.and a reservoir normally at atmospheric pressure connected to said piston chamber and communicating with the fluid pressure side of the piston upon movement of the piston by fluid pressure.

In testimony whereof I have hereunto set my hand.

. WALTER V. TURNER. 

